[thopok]

Stavio sam: "On multiprocessors, use at most 1 processors"

Tu je problem. BOINC u toj verziji vidi 1 CPU.

Maximum number of processors to use
On a multiprocessor, this limits the number of processors that BOINC will use. As of 6.1, the option works as a % selector of total available processor cores.

a meni je zadnjih pol sata 100%

Konstantno? Ili kao ovdje?

Yes, if you set your General Preference to use at most 50% of CPU for example, then it will use 100% CPU for a second, then do nothing for a second, then use 100% for a second... this gives you the 50% usage on average.

Ako i dalje stanje nije zadovoljavajuće, smanji još više % of CPU time.

Install a utility that monitors CPU temperature, such as Motherboard Monitor

Što se tiče add-on-a, tu je BES koji ima GUI. A opet radi isto što i ugrađeni:

You might want to set the maximum CPU load in the absolute percentage (e.g. “make it exactly 40% whenever possible”), but BES can't do that; because BES is not controlling the CPU directly in low level, but indirectly limits the “greediness” of the target application (i.e. how often it requests the system to give it a time slice) by forcing the targeted process to periodically sleep for a very short time. What you are actually controlling by setting % here is this “periodically how?” part.